HIGH-TEMPERATURE CREEP-BEHAVIOR OF SINGLE-CRYSTAL SUPERALLOY

Creep behaviour of a newly developed single crystal nickel base supera lloy DMSX-1 Ni-7.7Co-6.4Cr-8.4W-0.3Ti-5.57Al-7.6Ta-Nf-Y-Nb-Re, wt-%) w ith [001] orientation has been analysed and compared with the reported data of SRR99. It was concluded that the shear stress based model dev eloped for SRR99 is also applicable for the new alloy. Although the ma terial constants for octahedral slip for the new alloy are not exactly the same as those of SRR99, the estimated values of initial creep rat e and softening coefficients are nearly of the same order. Therefore i t is concluded that in the absence of a material database for cube sli p for this new alloy those available for SRR99 could be used to predic t the orientation dependence of its creep behaviour. (C) 1998 The Inst itute of Materials.